In the consumer electronics and computer industries, transmission of audio signals from a host player to remote device speakers has generally been accomplished over an analog wired interface comprising speaker. With the advent of digital audio content, the desire to maintain the pristine digital audio signal as far as possible along the audio signal chain has motivated designers to pursue digital interfaces to replace unsightly, signal-loss-prone analog speaker wires.
The High-Definition Multimedia Interface (HDMI) is an all-digital audio/video interface capable of transmitting uncompressed streams. HDMI is compatible with High-bandwidth Digital Content Protection (HDCP) Digital Rights Management technology. HDMI provides an interface between any compatible digital audio/video source, such as a set-top box, a DVD player, a PC, a video game console, or an audio video (AV) receiver and a compatible digital audio and/or video monitor, such as a digital television (DTV).
FIG. 1 shows an example of a conventional prior art audio video system that includes a source, HDMI AV receiver, with a centralized amplifier connected via an HDMI cable to HDMI DVD player and also connected via an HDMI cable to a display (HDMI TV). The HDMI AV receiver is also connected via analog speaker wires to a set of 6 speakers, each connected point-to-point from the HDMI AV receiver. Speakers in FIG. 1 are identified as follows: Front Left (FL), Front Right (FR), Center (C), Surround Left (SL), Surround Right (SR), and Low Frequency Effect (LFE), also commonly referred to as a “subwoofer.”
FIG. 1 contains components which can maintain pristine digital audio and video from source to display through HDMI interconnects. The interconnects from the source to the speakers still comprise analog via conventional speaker wires. For prior art systems containing 6 individual speakers, and other, more advanced systems that support up to 8 speakers or more, the speaker wire interconnections not only suffer from analog signal loss, but the speaker wire interconnections can be an eyesore or be a wire-hiding challenge.
Additionally, configuration and calibration of the speakers in FIG. 1 is performed with a wired analog microphone coupled by a wire to the HDMI AV receiver. Test tones are sent from the AV receiver to a test speaker, which reproduces the test tones. The wired microphone coupled to the AV receiver listens for the test tones reproduced by the test speaker. The AV receiver then calculates delay and volume parameters for the test speaker. The wired microphone is limited in its location and convenience of use by the wire coupled to the AV receiver. The wired microphone also provides analog audio input, rather than pristine digital audio.